Added string_indexing.lua and words_to_numbers.lua to the distribution

install/mushclient.nsi

@@ -364,9 +364,11 @@ SetOverwrite ifnewer
    File "..\lua\serialize.lua"
    File "..\lua\show_loaded.lua"  
    File "..\lua\strict.lua"
+   File "..\lua\string_indexing.lua"
    File "..\lua\tprint.lua"
    File "..\lua\var.lua"
    File "..\lua\wait.lua"
+   File "..\lua\words_to_numbers.lua"
    File "..\luacom\luacom5.lua"  
 
    ; LuaSocket
@@ -579,9 +581,11 @@ Section Uninstall
   Delete "$INSTDIR\lua\serialize.lua"
   Delete "$INSTDIR\lua\show_loaded.lua"  
   Delete "$INSTDIR\lua\strict.lua"
+  Delete "$INSTDIR\lua\string_indexing.lua"
   Delete "$INSTDIR\lua\tprint.lua"
   Delete "$INSTDIR\lua\var.lua"
   Delete "$INSTDIR\lua\wait.lua"
+  Delete "$INSTDIR\lua\words_to_numbers.lua"
 
   Delete "$INSTDIR\lua\socket.lua"
   Delete "$INSTDIR\lua\ltn12.lua"

lua/string_indexing.lua

@@ -0,0 +1,24 @@
+--[[
+
+  string_indexing.lua
+  
+  If you install this, then you can index into strings, like this:
+  
+  
+    require "string_indexing"
+    
+    a = "nick"
+    print (a [3])  --> c
+
+
+
+--]]
+
+getmetatable ("").__index = function (str, i)
+
+  if (type (i) == "number") then
+    return string.sub (str, i, i)  -- index into str
+  end -- if
+
+  return string [i]  -- fallback (eg. string.match)
+end -- function

lua/words_to_numbers.lua

@@ -0,0 +1,298 @@
+-- Convert a number to words
+-- Author: Nick Gammon
+-- Date: 18th March 2010
+
+-- See: http://www.gammon.com.au/forum/?id=10155
+
+-- Examples of use:
+--    words  = convert_numbers_to_words ("94921277802687490518")
+--    number = convert_words_to_numbers ("one hundred eight thousand three hundred nine")
+
+-- Both functions return nil and an error message so you can check for failure,
+-- or assert, eg. words = assert (convert_numbers_to_words ("2687490518"))
+
+-- Units, must be in inverse order!
+-- The trailing space is required as the space between words
+
+local inverse_units = {
+    "vigintillion ",     -- 10^63
+    "novemdecillion ",   -- 10^60
+    "octodecillion ",    -- 10^57
+    "septendecillion ",  -- 10^54
+    "sexdecillion ",     -- 10^51
+    "quindecillion ",    -- 10^48
+    "quattuordecillion ",-- 10^45
+    "tredecillion ",     -- 10^42
+    "duodecillion ",    -- 10^39
+    "undecillion ",     -- 10^36
+    "decillion ",       -- 10^33
+    "nonillion ",       -- 10^30
+    "octillion ",       -- 10^27
+    "septillion ",      -- 10^24
+    "sextillion ",      -- 10^21
+    "quintillion ",     -- 10^18
+    "quadrillion ",     -- 10^15
+    "trillion ",        -- 10^12
+    "billion ",         -- 10^9
+    "million ",         -- 10^6
+    "thousand ",        -- 10^3
+  } -- inverse_units
+
+local inverse_numbers = {
+    "one ",
+    "two ",
+    "three ",
+    "four ",
+    "five ",
+    "six ",
+    "seven ",
+    "eight ",
+    "nine ",
+    "ten ",
+    "eleven ",
+    "twelve ",
+    "thirteen ",
+    "fourteen ",
+    "fifteen ",
+    "sixteen ",
+    "seventeen ",
+    "eighteen ",
+    "nineteen ",
+    "twenty ",
+    [30] = "thirty ",
+    [40] = "forty ",
+    [50] = "fifty ",
+    [60] = "sixty ",
+    [70] = "seventy ",
+    [80] = "eighty ",
+    [90] = "ninety ",
+ }  -- inverse_numbers
+
+local function convert_up_to_999 (n)
+
+  if n <= 0 then
+    return ""
+  end -- if zero
+
+  local hundreds = math.floor (n / 100)
+  local tens = math.floor (n % 100)
+  local result = ""
+
+  -- if over 99 we need to say x hundred  
+  if hundreds > 0 then
+
+    result = inverse_numbers [hundreds] .. "hundred "
+    if tens == 0 then
+      return result
+    end -- if only a digit in the hundreds column
+
+  -- to have "and" between things like "hundred and ten"
+  -- uncomment the next line
+  --  result = result .. "and "
+
+  end -- if
+
+  -- up to twenty it is then just five hundred (and) fifteen
+  if tens <= 20 then
+    return result .. inverse_numbers [tens] 
+  end -- if
+
+  -- otherwise we need: thirty (something)
+  result = result .. inverse_numbers [math.floor (tens / 10) * 10] 
+
+  -- get final digit (eg. thirty four)
+  local digits = math.floor (n % 10)
+
+  -- to put a hyphen between things like "forty-two" 
+  -- uncomment the WITH HYPHEN line and 
+  -- comment out the NO HYPHEN line
+
+  if digits > 0 then
+    result = result ..  inverse_numbers [digits]  -- NO HYPHEN
+--    result = string.sub (result, 1, -2) .. "-" ..  inverse_numbers [digits]  -- WITH HYPHEN
+  end -- if 
+
+  return result
+
+end -- convert_up_to_999
+
+-- convert a number to words
+-- See: http://www.gammon.com.au/forum/?id=10155
+
+function convert_numbers_to_words (n)
+  local s = tostring (n)
+
+  -- preliminary sanity checks
+  local c = string.match (s, "%D")
+  if c then
+    return nil, "Non-numeric digit '" .. c .. "' in number"
+  end -- if
+
+  if #s == 0 then
+    return nil, "No number supplied"
+  elseif #s > 66 then
+    return nil, "Number too big to convert to words"
+  end -- if
+
+  -- make multiple of 3
+  while #s % 3 > 0 do
+    s = "0" .. s
+  end -- while
+
+  local result = ""
+  local start = #inverse_units - (#s / 3) + 2
+
+  for i = start, #inverse_units do
+    local group = tonumber (string.sub (s, 1, 3))
+    if group > 0 then
+      result = result .. convert_up_to_999 (group) .. inverse_units [i]
+    end -- if not zero
+    s = string.sub (s, 4)    
+  end -- for
+
+  result = result .. convert_up_to_999 (tonumber (s)) 
+
+  if result == "" then
+    result = "zero"
+  end -- if
+
+  return (string.gsub (result, " +$", ""))  -- trim trailing spaces
+
+end -- convert_numbers_to_words
+
+-- Convert words to a number
+-- Author: Nick Gammon
+-- Date: 18th March 2010
+
+-- Does NOT handle decimal places (eg. four point six)
+
+local numbers = {
+         zero       = bc.number (0),
+         one        = bc.number (1),
+         two        = bc.number (2),
+         three      = bc.number (3),
+         four       = bc.number (4),
+         five       = bc.number (5),
+         six        = bc.number (6),
+         seven      = bc.number (7),
+         eight      = bc.number (8),
+         nine       = bc.number (9),
+         ten        = bc.number (10),
+         eleven     = bc.number (11),
+         twelve     = bc.number (12),
+         thirteen   = bc.number (13),
+         fourteen   = bc.number (14),
+         fifteen    = bc.number (15),
+         sixteen    = bc.number (16),
+         seventeen  = bc.number (17),
+         eighteen   = bc.number (18),
+         nineteen   = bc.number (19),
+         twenty     = bc.number (20),
+         thirty     = bc.number (30),
+         forty      = bc.number (40),
+         fifty      = bc.number (50),
+         sixty      = bc.number (60),
+         seventy    = bc.number (70),
+         eighty     = bc.number (80),
+         ninety     = bc.number (90),
+} -- numbers 
+
+local units = {
+          hundred             = bc.number ("100"),
+          thousand            = bc.number ("1" .. string.rep ("0",  3)),
+          million             = bc.number ("1" .. string.rep ("0",  6)),
+          billion             = bc.number ("1" .. string.rep ("0",  9)),
+          trillion            = bc.number ("1" .. string.rep ("0", 12)),
+          quadrillion         = bc.number ("1" .. string.rep ("0", 15)),
+          quintillion         = bc.number ("1" .. string.rep ("0", 18)),
+          sextillion          = bc.number ("1" .. string.rep ("0", 21)),
+          septillion          = bc.number ("1" .. string.rep ("0", 24)),
+          octillion           = bc.number ("1" .. string.rep ("0", 27)),
+          nonillion           = bc.number ("1" .. string.rep ("0", 30)),
+          decillion           = bc.number ("1" .. string.rep ("0", 33)),
+          undecillion         = bc.number ("1" .. string.rep ("0", 36)),
+          duodecillion        = bc.number ("1" .. string.rep ("0", 39)),
+          tredecillion        = bc.number ("1" .. string.rep ("0", 42)),     
+          quattuordecillion   = bc.number ("1" .. string.rep ("0", 45)),
+          quindecillion       = bc.number ("1" .. string.rep ("0", 48)),    
+          sexdecillion        = bc.number ("1" .. string.rep ("0", 51)),     
+          septendecillion     = bc.number ("1" .. string.rep ("0", 54)),  
+          octodecillion       = bc.number ("1" .. string.rep ("0", 57)),    
+          novemdecillion      = bc.number ("1" .. string.rep ("0", 60)),   
+          vigintillion        = bc.number ("1" .. string.rep ("0", 63)),     
+  } -- units
+
+-- convert a number in words to a numeric form
+-- See: http://www.gammon.com.au/forum/?id=10155
+-- Thanks to David Haley
+
+function convert_words_to_numbers (s)
+
+  local stack = {}
+  local previous_type
+
+  for word in string.gmatch (s:lower (), "[%a%d]+") do
+    if word ~= "and" then  -- skip "and" (like "hundred and fifty two")
+      local top = #stack
+
+      -- If the current word is a number (English or numeric), 
+      -- and the previous word was also a number, pop the previous number 
+      -- from the stack and push the addition of the two numbers. 
+      -- Otherwise, push the new number.
+
+      local number = tonumber (word)  -- try for numeric (eg. 22 thousand)
+
+      if number then
+        number = bc.number (number)   -- turn into "big number"
+      else
+        number = numbers [word]
+      end -- if a number-word "like: twenty"
+
+      if number then
+        if previous_type == "number" then   -- eg. forty three
+          local previous_number = table.remove (stack, top)  -- get the forty
+          number = number + previous_number  -- add three
+        end -- if 
+        table.insert (stack, number)   
+        previous_type = "number"
+      else
+
+        -- If the current word is a unit, multiply the number on the top of the stack by the unit's magnitude. 
+        local unit = units [word]
+        if not unit then
+          return nil, "Unexpected word: " .. word
+        end -- not unit
+        previous_type = "unit"
+
+        -- It is an error to get a unit before a number.
+
+        if top == 0 then
+          return nil, "Cannot have unit before a number: " .. word
+        end -- starts of with something like "thousand"
+
+        -- pop until we get something larger on the stack
+        local interim_result = bc.number (0)
+        while top > 0 and stack [top] < unit do
+          interim_result = interim_result + table.remove (stack, top)
+          top = #stack
+        end -- while
+        table.insert (stack, interim_result * unit)
+
+      end -- if number or not
+    end -- if 'and'
+
+  end -- for each word
+
+  if #stack == 0 then
+    return nil, "No number found"
+  end -- nothing
+
+  -- When the input has been parsed, sum all numbers on the stack.
+
+  local result = bc.number (0)
+  for _, item in ipairs (stack) do
+    result = result + item
+  end -- for
+
+  return result
+end -- function convert_words_to_numbers